Using Unique Identifiers to Retrieve Configuration Data for Tag Devices

ABSTRACT

Methods and systems for using unique identifiers to retrieve configuration data for tag devices are described herein. An example method may involve obtaining a unique identifier associated with a tag device. The tag device may include an antenna and a sensor configured to obtain sensor readings that can be wirelessly transmitted to a reader device via the antenna. The method may also involve determining configuration parameters associated with the tag device based on the unique identifier. The method may further involve storing, in at least one memory, at least a portion of the configuration parameters in association with the unique identifier.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

Radio-frequency identification (RFID) systems implement wirelesstransference of data utilizing radio-frequency (RF) electromagneticfields. Such systems may include a reader device, often referred to asan “interrogator,” and a tag device, often referred to as a “label.” Insome scenarios, RFID tag devices can be included in objects in order toidentify and/or track the objects using the reader device.

RFID systems can be classified by whether the tag device is “active” or“passive.” In an example system, a reader device may transmit an RFinterrogator signal to a passive tag device, thereby directing thepassive tag device to reply to the interrogator signal by transmittingan information signal back to the reader device.

SUMMARY

In a first aspect, a method is provided. The method includes obtaining aunique identifier associated with a tag device, where the tag deviceincludes an antenna and a sensor configured to obtain sensor readingsthat can be wirelessly transmitted to a reader device via the antenna.The method also includes determining, based on the unique identifier,configuration parameters associated with the tag device. The methodfurther includes storing, in at least one memory, at least a portion ofthe configuration parameters in association with the unique identifier.

In a second aspect, a computing device is provided. The computing devicecomprises at least one radio frequency (RF) transceiver unit, at leastone processor, and at least one memory, where the at least one memorystores instructions that upon execution by the at least one processorcause the computing device to perform operations. The operationscomprise obtaining a unique identifier associated with at least one tagdevice, where the at least one tag device includes an antenna and asensor configured to obtain sensor readings that can be wirelesslytransmitted to the computing system via the antenna. The operations alsocomprise determining, based on the unique identifier, configurationparameters associated with the at least one tag device. The operationsfurther comprise storing, in the at least one memory, at least a portionof the configuration parameters in association with the uniqueidentifier.

In a third aspect, a non-transitory computer readable medium havingstored instructions is provided. The instructions are executable by acomputing device to cause the computing device to perform functions. Thefunctions include obtaining a unique identifier associated with a tagdevice, where the tag device includes an antenna and a sensor configuredto obtain sensor readings that can be wirelessly transmitted to thecomputing device via the antenna. The functions also includedetermining, based on the unique identifier, configuration parametersassociated with the tag device. The functions further include storing,in at least one memory, at least a portion of the configurationparameters in association with the unique identifier.

These as well as other aspects, advantages, and alternatives, willbecome apparent to those of ordinary skill in the art by reading thefollowing detailed description, with reference where appropriate to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system with a tag device in wirelesscommunication with a reader device, according to an example embodiment.

FIG. 2 is a flow chart illustrating an example method according to anexample embodiment.

FIGS. 3A-3B are block diagrams of an example system configured toimplement the example method, according to an example embodiment.

FIGS. 4A-4B are views of an example eye-mountable device, according toan example embodiment.

DETAILED DESCRIPTION

The following detailed description describes various features andfunctions of the disclosed systems and methods with reference to theaccompanying figures. In the figures, similar symbols typically identifysimilar components, unless context dictates otherwise. The illustrativemethod and system embodiments described herein are not meant to belimiting. It will be readily understood that certain aspects of thedisclosed methods and systems can be arranged and combined in a widevariety of different configurations, all of which are contemplatedherein.

I. OVERVIEW

When a tag device is implemented without non-volatile memory,device-specific information, such as calibration information (or otherconfiguration parameters), historical sensor readings (or otheruser-specific information) can be stored in a reader device or in adatabase accessible to the reader device. To associate suchdevice-specific information with a particular tag device, the tag devicecan be configured to generate and output a distinctive signature, suchas a substantially unique identification sequence. The identificationsequence can be communicated to the reader device, which can thenassociate a particular tag device with corresponding device-specificinformation using the substantially unique identification sequence todistinguish between different tag devices. The substantially uniqueidentification sequence can be a data series that can be repeatedly(i.e., consistently) generated by the tag device in response to aninterrogation signal. In some cases, the data series is hard-coded intothe control electronics of the tag device (e.g., during devicemanufacture) akin to a serial number. In some cases, the data series isgenerated dynamically (but substantially repeatably) in accordance withprocess variations in a series of semiconductive circuit components. Forinstance, a series of binary bits can be constructed from the output ofa set of comparator circuits that each settle in one state or anotherdepending on the difference in threshold voltage between two thin-filmtransistors.

Configuring the tag device without non-volatile memory, and insteadstoring device-specific information in the reader device or in adatabase accessible to the reader device, allows the tag device tooperate at a reduced power budget. Historical sensor readings for aparticular user can also be loaded to a reader device or database toallow the user to track readings over time, without relying on theresiliency/longevity of any one particular tag device, which may bedisposable. In addition, such tag devices can be disposed without losingany user-specific or user-sensitive information (e.g., bio-sensormeasurements, temperature measurements, etc.), because such informationis stored only on the reader device and/or networked database.

An example method can be implemented by a reader device (and/or by atleast one other computing device) to identify one or multiple tagdevices that do not have non-volatile memory. The example method canalso be implemented to obtain configuration parameters for theidentified tag device(s) and/or other information relevant to theidentified tag device(s). Such configuration parameters and/or otherinformation can then be transmitted by the reader device to the tagdevice(s), stored locally at the reader device, and/or stored remotelyat another computing device, such as a smartphone.

In an example embodiment, a tag device including at least an antenna anda sensor can be in communication with a reader device that is configuredto transmit a signal to the tag device, such as a signal including datato provide to the tag device and/or an interrogation signal to promptthe tag device to transmit information back to the reader device. Thereader device can also be in communication with a server, at whichconfiguration parameters for the tag device may be stored. In thisembodiment, the reader device may be configured to obtain a(substantially) unique identifier associated with the tag device. Theunique identifier may include information associated with where the tagdevice was fabricated, when it was fabricated, and/or other tag devicesthat it was fabricated with. Further, the unique identifier may take theform of a substantially unique bit sequence that is generated when thetag device is initially calibrated and configured, such as thesubstantially unique identification sequence noted above.

The reader device can obtain the unique identifier in various ways. Byway of example, the reader device may be configured to scan an opticalcode associated with the tag device to obtain the unique identifier. Theoptical code may be a Quick Response (QR) code, and may be presented onpackaging for the tag device, for example. The optical code may haveencoded the unique identifier of the tag device. Other methods can beused by the reader device to obtain the unique identifier as well. Forexample, the unique identifier can be embedded or otherwise stored in anRFID-readable device associated with the tag device, such as another tagdevice. As such, the reader device may be configured to interrogate theRFID-readable device in order to obtain the unique identifier. As afurther example, the unique identifier can be obtained from the tagdevice itself by interrogating the tag device.

After obtaining the unique identifier of the tag device, the readerdevice may transmit the unique identifier to the server, andresponsively receive the configuration parameters from the server basedon the unique identifier. The reader device may then store a portion ofthe configuration parameters in its memory. Further, in some scenarios,the reader device may also transmit another portion of the configurationparameters to the tag device. Upon receiving the configurationparameters, the tag device may be enabled to use the configurationparameters to configure one or more of its components, such as itssensor and/or other circuitry. The tag device's sensor may be configuredto obtain sensor readings (e.g., data) that can be wirelesslytransmitted by the antenna of the tag device and received by the readerdevice. Further, the reader device may be configured to use itsrespective portion of the configuration parameters in accordance withdata received from the tag device in order to determine/estimateinformation about the tag device (e.g., a temperature of the tag device,glucose or other analyte readings obtained by the tag device, etc.).

In another example embodiment, a mobile computing device, such as asmartphone, can be used to obtain the unique identifier. By way ofexample, the mobile computing device may be configured to scan theoptical code (or multiple optical codes, in some scenarios). The mobilecomputing device may be configured to function as a reader device, ormay function as an intermediary between the reader device and theserver. The mobile computing device may also be configured to storemultiple identifiers and parameters associated with multiple tagdevices. For instance, many tag devices may be packaged together and asingle optical code may be used to identify them. Upon scanning thesignal optical code with the mobile computing device, the mobilecomputing device may obtain identifiers for each tag device, transmitthe identifiers to the server, and responsively receive configurationparameters associated with each tag device. The mobile computing devicemay transmit some or all of the configuration parameters to the readerdevice.

II. EXAMPLE COMMUNICATION SYSTEM

FIG. 1 is a block diagram of a system 100 that includes a tag device 110in wireless communication with a reader device 160. The tag device 110may include a power supply 120, a controller 130, sensing electronics140, and a communication antenna 150. The tag device may also includeother electronics not shown in FIG. 1. The sensing electronics 140 areoperated by the controller 130. The power supply 120 (e.g., arectifier/regulator component of the power supply 120) supplies andrectifies/regulates operating voltages, such as a DC supply voltage 121,to the controller 130 and/or the sensing electronics 140. The antenna150 is operated by the controller 130 to communicate information toand/or from the tag device 110.

In some embodiments, the power supply 120 may be coupled to (or include)one or more batteries (not shown). The one or more batteries may berechargeable and each battery may be recharged via a wired connectionbetween the battery and a power supply 120 and/or via a wirelesscharging system, such as an inductive charging system that applies anexternal time-varying magnetic field to an internal battery.

In some embodiments, the power supply 120 may be configured to harvestambient energy to power the controller 130 and the sensing electronics140. For example, the power supply 120 may include an RFenergy-harvesting antenna configured to capture energy from incidentradio radiation provided by the reader device 160. Moreover, the tagdevice 110 may receive all of its operating energy from an RF signaltransmitted by the reader device 160. Additionally or alternatively tothe RF energy-harvesting antenna, the power supply 120 may include solarcell(s) (“photovoltaic cells”) configured to capture energy fromincoming ultraviolet, visible, and/or infrared radiation. Otherembodiments are also possible.

The controller 130 is turned on when the DC supply voltage 121 isprovided to the controller 130, and the logic in the controller 130operates the sensing electronics 140 and the antenna 150. The controller130 can include logic circuitry, such as a sensor interface module 132,configured to operate the sensing electronics 140 so as to interact witha surrounding environment of the tag device 110.

The controller 130 can also include a communication circuit 134 forsending and/or receiving information via the antenna 130. Thecommunication circuit 134 can optionally include one or moreoscillators, mixers, frequency injectors, etc. to modulate and/ordemodulate information on a carrier frequency to be transmitted and/orreceived by the antenna 150. In some examples, the tag device 110 isconfigured to indicate an output from the temperature-sensingelectronics 140 by modulating an impedance of the antenna 150 in amanner that is perceivable by the reader device 160. For example, thecommunication circuit 134 can cause variations in the amplitude, phase,and/or frequency of backscatter radiation from the antenna 150, and suchvariations can be detected by the reader device 160. In someembodiments, after the reader device 160 transmits an RF signal to thetag device 110, the reader device 160 can receive indications of resultsfrom the sensing electronics 140 (e.g., data associated with theelectronic oscillator 142, data associated with the analyte bio-sensor144, and/or other data) transmitted back to the reader device 160 by thebackscatter radiation, the backscatter radiation being at a givenfrequency.

The controller 130 is connected to the sensing electronics 140 viainterconnects 135. For example, where the controller 130 includes logicelements implemented in an integrated circuit to form the sensorinterface module 132, a patterned conductive material (e.g., gold,platinum, palladium, titanium, copper, aluminum, silver, metals,combinations of these, etc.) can connect a terminal on the chip to thetemperature-sensing electronics 140. Similarly, the controller 130 isconnected to the antenna 150 via interconnects 136.

It is noted that the block diagram shown in FIG. 1 is described inconnection with functional modules for convenience in description.However, embodiments of the tag device 110 can be arranged with one ormore of the functional modules (“sub-systems”) implemented in a singlechip, integrated circuit, and/or physical component. For example, thefunctional blocks in FIG. 1 shown as the power supply block 120 andcontroller block 130 need not be implemented as physically separatedmodules. Moreover, one or more of the functional modules described inFIG. 1 can be implemented by separately packaged chips electricallyconnected to one another.

The identification sequence generator 138 can be configured to output aunique identifier (e.g., an identification sequence). The uniqueidentifier can be a substantially unique series of values (e.g., aseries of binary values) that provide a unique characterizing“fingerprint” for use in distinguishing the tag device 110 from othertag devices. In accordance with the method described herein, the uniqueidentifier may be communicated by the tag device 110 to the readerdevice 160 to be used by the reader device 160 to retrieve informationassociated with the tag device 110. A record of the unique identifiermay also be stored outside of the system 100 shown in FIG. 1, such as ata server or mobile computing device.

The sensing electronics 140 may include an electronic oscillator 142.The electronic oscillator 142 may include a relaxation oscillator, suchas a ring oscillator, or a particular modification of the relaxationoscillator. The electronic oscillator 142 may be utilized, for example,for sensing a temperature of the tag device 110. In other examples, theelectronic oscillator 142 can be configured to be sensitive to otherparameters, such as light, movement, and humidity, in addition to oralternatively to temperature. As such, the electronic oscillator 142 canbe used to estimate parameters not just of the tag device 110, but ofthe tag device's surrounding environment.

The sensing electronics 140 may also include a frequency divider circuit(not shown), which can be used in accordance with the electronicoscillator 142 and/or other components of the sensing electronics 140,such as the analyte bio-sensor and/or other components not describedherein. The frequency divider circuit may include a standard frequencydivider configured to generate an output signal of a frequency based onan input signal of a frequency. For example, the tag device 110 maygenerate an RF signal of a resulting frequency based on the oscillatorfrequency of the electronic oscillator 142. In some embodiments, thefrequency divider circuit of the tag device 110 may be a component of afrequency synthesizer system configured to generate any resultingfrequency that is within a given range of frequencies (e.g., within anoptimal range of frequencies for the tag device 110 to operate at). Thegiven range may be based on the type of tag device (e.g., high-frequencyRFID tag or ultra-high-frequency RFID tag). The resulting frequency maybe generated from a single oscillator, such as the electronic oscillator142. Further, the resulting frequency can be generated by the frequencysynthesizer system based on frequency multiplication, frequencydivision, and/or frequency mixing. In some embodiments, the sensingelectronics 140 may include a frequency adjuster component other than afrequency divider circuit, which may use a type of frequency adjustmentfactor to adjust/correct the oscillator frequency.

The sensing electronics 140 may include an analyte bio-sensor 144. Theanalyte bio-sensor 144 can be, for example, an amperometricelectrochemical sensor that includes a working electrode and a referenceelectrode. A voltage can be applied between the working and referenceelectrodes to cause an analyte (e.g., glucose) to undergo anelectrochemical reaction (e.g., a reduction and/or oxidation reaction)at the working electrode. The electrochemical reaction can generate anamperometric current that can be measured through the working electrode.The amperometric current can be dependent on the analyte concentration.Thus, the amount of the amperometric current that is measured throughthe working electrode can provide an indication of analyteconcentration. In some embodiments, the sensor interface module 144 canbe a potentiostat configured to apply a voltage difference betweenworking and reference electrodes while measuring a current through theworking electrode.

It should be understood that components of the sensing electronics 140described above may have other functionalities related to the operationof the tag device 110 other than sensing parameters of the tag device'senvironment, and thus the description of their functions should not belimited to the description herein.

The reader device 160 includes an antenna 168 (or a group of more thanone antennae) to send and receive wireless signals, such as RF signals,to and from the tag device 110. The reader device reader 160 alsoincludes a computing system with a processor 166 in communication with amemory 162. The memory 162 is a non-transitory computer-readable mediumthat can include, without limitation, magnetic disks, optical disks,organic memory, and/or any other volatile (e.g. RAM) or non-volatile(e.g. ROM) storage system readable by the processor 166. The memory 162can include a data storage 163 to store indications of data, such assensor readings, program settings (e.g., to adjust behavior of the tagdevice 110 and/or the reader device 160), etc. The memory 162 can alsoinclude program instructions 164 for execution by the processor 166 tocause the reader device 160 to perform processes specified by theinstructions 164. For example, the program instructions 164 can causethe reader device 160 to provide a user interface that allows forretrieving information communicated from the tag device 110 (e.g.,outputs from the sensing electronics 140). The reader device 160 canalso include one or more hardware components for operating the antenna168 to send and receive the wireless signals to and from the tag device110. For example, oscillators, frequency injectors, encoders, decoders,amplifiers, filters, etc. can drive the antenna 168 according toinstructions from the processor 166.

The reader device 160 can be a smart phone, digital assistant, or otherportable computing device with wireless connectivity sufficient toprovide the wireless communication link 161. The reader device 160 canalso be implemented as an antenna module that can be plugged in to aportable computing device, such as in an example where the communicationlink 161 operates at carrier frequencies not commonly employed inportable computing devices. In some embodiments, the tag device 110 maybe implemented in an eye-mountable device (e.g., a contact lens) so asto sense a temperature of the eye-mountable device. In such embodiments,the reader device 160 may be configured to be worn relatively near awearer's eye to allow the wireless communication link 161 to operatewith a low power budget. For example, the reader device 160 can beintegrated in eyeglasses, jewelry, or integrated in an article ofclothing worn near the head, such as a hat, headband, etc.

In some embodiments, the tag device 110 and reader device 160 includeone or more wireless interfaces so as to communicate with each otherusing a radio-frequency ID (RFID) protocol. For example, the tag device110 and reader device 160 can communicate with each other in accordancewith a Gen2 ultra-high frequency (UHF) RFID protocol, under which thesystem 100 operates in a frequency range of 860 MHz to 960 MHz. Further,under the Gen2 UHF RFID protocol, the system 100 may be apassive-backscatter system in which the reader device 160 transmitsinformation to the tag device 110 by modulating an RF signal in the 860MHz to 960 MHz frequency range. Still further, the passive tag device110 can receive its operating energy from the RF signal, as noted above,and can modulate the reflection coefficient of its antenna in order tobackscatter a signal to the reader device 160 (after being directed todo so by the reader device 160, e.g., an “interrogator-talks-first”system). Other RFID protocols are also possible.

In some embodiments, the system 100 can operate to non-continuously(“intermittently”) supply energy to the tag device 110 to power thecontroller 130 and sensing electronics 140 (e.g., a passive system). Forexample, RF radiation can be supplied to power the tag device 110 longenough to carry out a sensor reading and communicate the results.Further, the supplied RF radiation can be considered an interrogationsignal from the reader device 160 to the tag device 110 to request asensor reading or other information to be acquired and sent back to thereader device 160. By periodically interrogating the tag device 110(e.g., by supplying RF radiation 161 to temporarily turn the device on)and storing the sensor results (e.g., via the data storage 163), thereader device 160 can accumulate a set of data/measurements over timewithout continuously powering the tag device 110.

III. EXAMPLE METHODS AND SCENARIOS

FIG. 2 is a flow chart illustrating an example method 200 according toan example embodiment. The example method 200 will be describedhereafter in conjunction with FIG. 3A, which illustrates an examplesystem 300 configured to implement the example method 200. Although theexample method 200 is described below as carried out by a reader device,it should be understood that the example method 200 can be carried out,additionally or alternatively, by one or more other devices as well,such as a mobile computing device, a wearable computing device, and anyaforementioned devices.

At step 202, the reader device 302 obtains a unique identifierassociated with a tag device 306. The tag device 306, such as a RFIDtag, may include an antenna and a sensor configured to obtain sensorreadings that can be wirelessly transmitted to the reader device 302 viathe antenna. The unique identifier for a particular tag device may be aunique identifier that was determined during an initial “factory-level”calibration and configuration of the particular tag device (e.g.,initial sensor calibration, setting initial oscillator tuning levels,etc.). Alternatively, the unique identifier may have been determined atanother point in time, or may be determined during the process ofobtaining it (e.g., the reader device interrogates the tag device orother tag device that provides or determines the unique identifier).

As noted above, the unique identifier can be obtained in various ways.It should be understood that while the example method 200 is describedherein in conjunction with the example system 300 of FIG. 3, in whichthe unique identifier is obtained by scanning an optical code 304, theunique identifier may be obtained in other ways including, but notlimited to, those described above.

With respect to the example system 300, the reader device 302 may scanan optical code 304, such as a Quick Response (QR) code or othermachine-readable code, associated with a tag device 306 (or multiple tagdevices) in order to obtain the unique identifier. The optical code 304may encode the unique identifier. The scanning of the optical code 304can also be performed by a computing device 308, such as a smartphone,laptop computer, tablet computer, desktop computer, etc., that is inwired and/or wireless communication with the reader device 302 and/orwith a server 310 at which information associated with the tag device(s)306 may be stored (e.g., a web server). As noted above, other types ofcomputing devices, such as a wearable computing device, can also beconfigured to obtain the unique identifier (and/or perform any otherfunctions described herein).

In some embodiments, additional information associated with the tagdevice(s) 306 may be included with the unique identifier (or remotelyfrom the unique identifier) and may be obtained as well by at least thesame means as the reader device 302 obtains the unique identifier. Forexample, the optical code 304 may also encode the additionalinformation. The additional information may take the form of a header,and may include manufacture information of the tag device(s) 306, suchas at least one timestamp indicating when the tag device(s) weremanufactured, calibrated, and/or shipped (e.g., production date,calibration date, shipment date, etc.). The manufacture information mayalso include a lot number representative of a group of tag devices thata particular tag device was manufactured with. Other information canalso be included as part of the additional information, such as aparticular tag device's expiration date. Additionally or alternativelyto being encoded in the optical code 304, it is possible for some or alladditional information to be included on the tag device 306 itself, viamasking and/or other methods, or included on/at another device.

The unique identifier and additional information can be hard coded tothe optical code 304, and the optical code 304 may be included on apackaging of the tag device(s) 306. In an example embodiment, anindividual tag device may include a respective optical code included onpackaging for the individual tag device. In such an embodiment, a largerpackaging can be used for multiple tag devices, each tag device with itsown optical code. Additionally or alternatively, in another exampleembodiment, the larger packaging may include an optical code thatencodes information for each tag device contained in the largerpackaging (e.g., one optical code associated with every tag device inthe packaging rather than multiple optical codes, each associated with aparticular tag device in the packaging). In such other embodiments, theoptical code may encode the unique identifiers of each tag devicecontained in the larger packaging.

At step 204, the reader device 302 (and/or the computing device 308, insome examples) determines, based on the scanned optical code 304, theunique identifier and configuration parameters associated with the tagdevice 306 (or tag devices, if the optical code encodes multiple uniqueidentifiers for multiple tag devices). When the reader device 302 scansthe optical code 304, it may retrieve the unique identifier of the tagdevice 306 encoded in the optical code 304. The reader device 302 maythen transmit the unique identifier to the server 310 and/or other suchdatabase(s) which may be utilized to look up the configurationparameters associated with the tag device 306. The reader device 302 maythen receive the configuration parameters from the server.

For tag devices equipped with electrochemical bio-sensors, temperaturesensors, and other sensors, the configuration parameters may includesensor calibration information associated with the tag device's sensoror other components of the tag device 306. In other embodiments, theconfiguration parameters may also include calibration informationassociated with one or more components of the reader device 302 and/orthe computing device 308. The calibration information may relate tointerpreting results from the tag device 306. For example, thecalibration information may be used by the reader device 302 ininterpreting the sensor readings as indications of analyte levels (e.g.,mapping sensor readings to analyte concentrations), as indications oftemperature, or as indications of other parameters. The calibrationinformation may be based on a manufacturing batch of a particular tagdevice (e.g., lot number). Additionally or alternatively, calibrationinformation may be based on previously obtained calibration results fora particular tag device. The configuration parameters may additionallyor alternatively include sensor configuration information and/or userpreferences for operating the sensor (e.g., voltage offset settings,sensor stabilization durations, measurement frequencies, etc.). Suchconfiguration information can then be used to cause the tag device 306to obtain measurements in accordance with the configuration information.For example, an indication of sensor stabilization time can cause thereader to initiate a stabilization operation prior to obtaining a sensormeasurement with a duration specified in the configuration information.

In addition to the sensor calibration information, other tagdevice-specific information can be stored at the server 310 (and/orother databases). Such other tag device-specific information may includedevice manufacture information (e.g., lot number identification,production date, shipment date, expiration date, serial number, etc.),associated user information (e.g., user identity, userconfiguration/profile information, such as number or frequency ofmeasurements to perform for the particular user, predetermined alertlevels, etc.), and/or device usage history (e.g., historical sensormeasurements, time since last usage, time since last calibration, etc.).Other examples of tag device-specific information are also possible asthe examples provided herein are generally included by way of exampleand not limitation. It should be understood, however, that while tagdevice-specific information can include user-specific information, suchuser-specific information may not be tethered to the identity ofindividual users of the tag device(s). Further, users of the tagdevice(s) can elect not to participate in collection of suchuser-specific information.

In some embodiments, at least a portion of the configuration parameters,such as calibration information associated with at least one tag device306, can be encoded in the optical code 304 on a packaging of the atleast one tag device 306. In such embodiments, the computing device 308(or reader device 302, in similar embodiments) can scan the optical code304 and subsequently download some or all of the aforementionedconfiguration parameters of the tag device(s) 306 (including at least aunique identifier for each tag device) so as to temporarily orpermanently store the configuration parameters in a database at thecomputing device 308 and/or at other devices. By doing so, the computingdevice 308 can refer to its own database instead of having to scan theoptical code 304 more than an initial scan and communicate with theserver 310 every time configuration information is desired. Theconfiguration parameters, including calibration information for the tagdevice(s) 306, may be stored in a database.

At step 206, the reader device 302 (and/or the computing device 308, insome examples) stores, in at least one memory, at least a portion of theconfiguration parameters in associated with the unique identifier. Theat least one memory can be included in one or more of the reader device302, the computing device 308, and other computing device(s) incommunication with the devices of the system 300 illustrated in FIG. 3A.

The portion of the configuration parameters may include, for example,calibration information associated with the sensor of the tag device306, such that measured values can be determined based on the sensorreadings and the calibration information. In some scenarios, the readerdevice 302 can use an RF signal to prompt the tag device 306 to obtain asensor reading. The tag device 306 may then transmit, via backscatterradiation, data representative of the sensor reading, datarepresentative of the tag device's unique identifier, and possibly otherinformation. Upon receiving the sensor reading, the reader device 302may then retrieve, from the at least one memory, the calibrationinformation (e.g., calibration curves) and other relevant information ofthe first portion of the configuration parameters based on the uniqueidentifier. The reader device 302 can also retrieve the calibrationinformation using header data associated with the tag device 306, suchas the tag device's lot number, production date, etc., as noted above.The reader device 302 can then determine a measured value based on thesensor reading and the first portion of the configuration parameters(e.g., compare the sensor reading to data points of the calibrationcurve to estimate/determine the measured value).

In some embodiments, upon receiving the unique identifier from the tagdevice 306 (the unique identifier being substantially unique due toreasons described below with respect to FIG. 3B), the reader device 302may refer to a database of tag-device specific information that wasstored in its memory after obtaining the unique identifier (e.g.,scanning the optical code) in order to verify the identity of the tagdevice 306 (or a user of the tag device). Alternatively, the readerdevice 302 may query the computing device 308 and/or the server 310 inorder to refer to the database. The reader device 302 may then check thedatabase to determine which unique identifier in the database is closestto or identical to the unique identifier received from the tag device306. It should be understood that while the tag device 306 may beconfigured to communicate its unique identifier in response to aninterrogation signal from the reader device 302, the reader device 302may not need to use the unique identifier received from the tag device306 in some scenarios, and may instead refer to a unique identifierassociated with the tag device 306 that is already stored in memoryresponsive to the obtaining of the unique identifier by the readerdevice 302 and/or other devices.

In some embodiments, in addition to storing the portion (i.e., a firstportion) of the configuration parameters at the reader device 302 and/orother device(s), the reader device 302 (and/or the computing device 308,in some examples) communicates at least another portion (i.e., a secondportion) of the configuration parameters to the tag device 306. Inexamples where the computing device 308 performs the obtaining describedat step 202, the computing device 308 may subsequently download from aserver 110 a first portion of the configuration parameters associatedwith a particular tag device to store either locally at the computingdevice 308 or remotely at the reader device 302. The computing device308 may also download a second portion of the configuration parametersof the particular tag device and communicate the second portion to theparticular tag device.

The second portion of the configuration parameters may relate toparameters that can be utilized for configuring at least one componentof the tag device, such as an electronic oscillator of the tag device(e.g., a ring oscillator), an analyte bio-sensor of the tag device, anRF transceiver, a voltage reference, a current reference, and/or othercircuitry/components. As such, the tag device 306 can be configured toprovide a sensor reading to the reader device 302 after receiving aninterrogation signal from the reader device 302. The reader device 302can then interpret the sensor reading using the first portion ofconfiguration parameters, such as calibration information associatedwith the tag device 306.

In an example scenario of the reader device interpreting a sensorreading using calibration information, the reader device may obtain asensor reading from the tag device, such as an eye-mountable device(e.g., a tag device embedded in a contact lens) equipped with anelectronic oscillator. For instance, the reader device can transmit RFradiation to the eye-mountable device, the eye-mountable can thenperform a measurement and modulate backscatter radiation to indicate themeasured frequency of the electronic oscillator, and the reader devicecan receive the indication of the measurement. The RF radiation mayindicate a reference frequency or other information as well that may beneeded in order to enable the eye-mountable device to perform themeasurement. The reader device can then use calibration informationincluded in the first portion of configuration parameters retrieved froma database and stored at the reader device to estimate/determine atemperature of the eye-mountable device corresponding to the receivedmeasured oscillator frequency. To do so, the first portion ofconfiguration parameters may include a calibration curve relating theoscillator frequency of the eye-mountable device and a temperature ofthe eye-mountable device. Other types of calibration curves andcalibration information are possible, and other example scenarios arepossible as well.

FIG. 3B is a detailed block diagram of a system 350 with tag device 364in communication with a reader device 352, similar to the tag devices110, 306 and reader devices 160, 302 of FIGS. 1 and 3A. The tag device364 can operate to output a unique identifier (e.g., a substantiallyunique identification sequence) and communicate the unique identifier tothe reader device 352. Using the unique identifier, the reader device352 can then retrieve and/or store data specific to the particular tagdevice 364, such as configuration and/or calibration information. Thereader device 352 can differentiate between different tag devices, usingthe unique identifiers from each, and associate tag device-specific datawith each device. As such, the tag device 364 does not have any need fornon-volatile memory to store data. Instead, the reader device 352 (or adatabase accessible by the reader device 352, such as a database at amobile computing device and/or server) can store tag device-specificinformation in a manner that associates the stored information with theunique identifiers of the tag device 364.

The reader device 352 includes a processing system 353, an optical codescanner 354 for scanning machine-readable code, and a memory 356. Thememory 356 can be a volatile and/or non-volatile computer readable medialocated in the reader device 352 and/or in network communication withthe reader device 352. The memory 356 can be similar to, for example,the memory 162 in the reader device 160 discussed with regard to FIG. 1above. The processing system 353 can be a computing system that executessoftware stored in the memory 356 to cause the system 350 to operate asdescribed herein. The reader device 352 may be incorporated into awearable device, such as a device configured to be worn relatively neara user's eye, such as a hat, a headband, an earring, a pendant, eyeglasses, etc. The reader device 352 may also be incorporated into awatch, a mobile phone, or another personal electronics device.

In some examples, the reader device 352 may obtain one or moremeasurements from sensor(s) on the tag device 364 (e.g., byintermittently transmitting a measurement signal to cause anelectrochemical sensor included in the tag device 364 to obtain ameasurement and communicate the results). The reader device 352 can alsoinclude an antenna (not shown) (e.g., an RF transceiver unit) fortransmitting RF radiation 360 to be harvested by the tag device 364. Thereader device 352 can also receive information transmitted back to thereader by backscatter radiation 362. For example, the antenna impedanceof the tag device 364 can be modulated in accordance with a uniqueidentifier such that the backscatter radiation 362 indicates the uniqueidentifier. The backscatter radiation 362 may also indicate sensormeasurements and oscillator frequency readings, among other examples.The reader device 352 can also use the memory 356 to store indicationsof tag device-specific information 358 (e.g., amperometric currentmeasurements) communicated from the tag device 364. The reader device352 can also use the memory 356 to store other tag device-specificinformation 358 (e.g., calibration information) received from a mobiledevice, server, or other computing device after scanning an optical codeassociated with the tag device 364.

The tag device 364 can include communication electronics 366, anidentification sequence generator 368, an antenna 370, and at least onesensor 372 (which may include components found in the sensingelectronics 140 of the tag device 110 illustrated in FIG. 1). As notedabove with respect to FIG. 1, the identification sequence generator 368can be configured to output a unique identifier (e.g., an identificationsequence). The unique identifier can be a substantially unique series ofvalues (e.g., a series of binary values) that provide a uniquecharacterizing “fingerprint” for use in distinguishing the particulartag device 364 from others. The sequence generator 368 can be configuredto repeatably (e.g., consistently) output the series in response to aprompt, such that the same particular device 364 can be consistentlyassociated with the same unique identifier. For example, theidentification sequence generator 368 can be a circuit that receives aprompt and outputs the unique identifier. The identification sequencegenerator 368 may be a circuit that is incorporated into a control chipof the tag device 364. In some examples, the unique identifier can be aserial number that is imprinted into the tag device 364 during amanufacturing process. For example, a circuit implementation of theidentification sequence generator 368 can be customized, duringmanufacture, to output a substantially unique series of high/low values.Each ophthalmic device that is produced can then be assigned a differentunique identifier, and the identification sequence generator circuits ofeach can be customized accordingly.

Additionally or alternatively, the identification sequence generator 368can be configured to generate the unique identifier for the tag device364 based on process variations in one or more circuit components. Forexample, a comparator circuit can be created that compares thresholdvoltages of two different transistors (or sets of transistors). Theuncorrelated threshold voltage variations in such pairs can be amplifiedand digitized to create a sequence of binary values depending on thestate of each comparator circuit. The individual binary state comparatorcircuits can each be formed from a comparator circuit (e.g., a latchcircuit) with cross-coupled logic gates. Following a reset, eachcomparator circuit settles on one of two possible states depending onthe random offset between the threshold voltages. Positive feedback inthe cross-coupled arrangement amplifies the small variations to allowfor readout. An array of many such circuits can then be used to create aunique identifier: an identification sequence with a desired number ofbits. Because the resulting identification sequence is based on random,uncorrelated variations in transistor threshold voltage (or otherprocess variations in the die, etc.), the identification sequence maynot be entirely unique (i.e., two different identification circuits maygenerate identical identification sequences). Moreover, such anidentification sequence generator 368 that relies on random processvariations may not consistently settle on the same output sequence. Forexample, comparisons between particularly close threshold voltages maynot consistently settle on the same value, and some circuits maysystematically change their output over time due to differentialdegradation of the compared circuit components. However, the probabilityof such ambiguities can be mitigated by using identification sequenceswith relatively greater word length (e.g., a greater number of bits,such as 128 bits).

In an example, the identification sequence generator 368 can includemultiple state circuits that are each configured to settle in one ofmultiple possible states, and each state circuit can then represent abit (or multiple bits) in the substantially unique identificationsequence. An example of such a state circuit can include a cross-coupledNOR gate. A pair of transistors can be arranged to cause the circuit tosettle in one state or another depending on the difference in thresholdvoltage between the two. Each transistor has a gate terminal, a sourceterminal, and a drain terminal. The conductivity between the drain andsource terminals is determined in part by the voltage applied across thegate and source terminals, with a gate-source voltage V_(gs) exceeding athreshold V_(th) resulting in a non-zero drain-source current I_(ds).The pair of transistors can be connected with the gate of the firsttransistor connected to the source of the second transistor and the gateof the second transistor connected to the source of the firsttransistor. The drain of each transistor can be connected to a supplyline and the source of each transistor can be connected to a groundline. The respective connections to the supply line and the ground linecan each be made through a transistor driven by a reset line. Uponresetting the circuit the source terminals and cross-coupled gateterminals are all set low (e.g., set to ground).

During the reset to low voltage one of the two cross-coupled transistorsbecomes conductive before the other one (e.g., the one with the lowerthreshold voltage). Current through the transistor that becomesconductive first creates positive feedback to increase the gate-sourcevoltage of the first conductive transistor while decreasing theconductivity of the second transistor, via the cross-coupled drain/gateconnection. The drains of the two cross-coupled transistors then settlewith one at a high voltage and one at a low voltage, depending on whichof the two transistors has a higher threshold voltage. Because thethreshold voltage V_(th) is a function of variations in the physicalproperties of the transistor channel regions (e.g., charge carriermobility, channel width and length, oxide conductance, etc.), either ofthe two states occur with roughly equal probability in a given cell dueto uncorrelated process variations in the manufacture of the circuit.The drains of the two transistors (or one of them) thus represents anoutput state of the example state circuit that settles in one ofmultiple possible states based on random process variations in themanufacture of the state circuit. Other state circuits based on processvariations in physical features in the constructed circuitry can also beemployed; the above state circuit is described for example purposesonly.

In some embodiments, upon receipt of backscatter radiation 362indicative of the unique identifier of the tag device 364 and a sensorreading obtained by the sensor(s) 372, the reader device 352 can use theunique identifier of the tag device 364 to access tag device-specificinformation 358 in the memory 356. For example, the reader device 352may lookup configuration parameters (e.g., calibration information, suchas calibration curves) for the tag device 364, a date of manufacture,production batch, shipment date, or expiration date of the tag device364, any information regarding prior use of the tag device 364, anparticular user associated with the tag device 364, etc. Such tagdevice-specific information 358 may be previously loaded to the memory356 in connection with manufacture, calibration, testing, or prioruse(s) of the device 364, for example. In addition, the reader device352 may supplement such tag device-specific information 358 withadditional sensor readings, user preferences, etc., such that theadditional information is associated with the unique identifier thatidentifies the particular tag device 364. Additionally or alternatively,the reader device 352 may access tag device-specific information storednon-locally (e.g., a database stored on a server in communication withthe reader device 352 or a database stored in memory on a smartphone incommunication with the reader device 352).

Once accessed, the tag device-specific information 358 can then be usedby the reader device 352 to operate the tag device 364. For example, thereader device 352 may use configuration parameters and other dataincluded in the tag device-specific information 358 to determine howoften (or under what conditions) to query the tag device 364 forreadings. In some embodiments, the configuration parameters may specifya desired amperometric current stabilization time for theelectrochemical sensor 372, and the reader device 352 may therefore beconfigured to instruct the tag device 364 to first apply a voltageacross electrodes in the sensor 372 for a period while the amperometriccurrent stabilizes (e.g., as the electrochemical reactions at theworking electrode reach a steady state). Following the stabilizationtime, the reader device 352 can then prompt the tag device 364 tomeasure the amperometric current and indicate the measured current viathe backscatter radiation 362. Other tag device-specific operationpreferences are also possible. Additionally or alternatively, the readerdevice 352 may use calibration information to interpret sensor readings(i.e., amperometric current measurements). Such calibration informationmay include, for example, a sensitivity and/or offset to define acalibration curve that relates current measurements to analyteconcentrations, a calibration curve that relates an oscillator frequencyof the tag device 364 to temperature, a calibration curve that relatescurrent supplied to the tag device 364 to temperature, among othercalibration information.

By storing tag device-specific information 358 off of the tag device364, and mapping such information to the tag device 364 using the(substantially) unique identifier output from the identificationsequence generator 368, the tag device 364 does not require on-boardprogrammable memory. As such, the memory-free tag device 364 does notstore any user-specific information (e.g., prior sensor readings, etc.).Such a memory-free configuration thereby alleviates potential privacyconcerns because user-specific information is stored on a platformsuitable for incorporating data-protection routines, such ascredentialed logins, encryption schemes, etc., which platform may be anycombination of the reader device 352, a mobile computing device that isin communication with the reader device 352, and/or other externalservers/devices. Moreover, the memory-free configuration alleviatesconcerns over losing data stored in the tag device 364 in the event oflosing the tag device 364. As such, the memory-free configurationdescribed herein facilitates implementations in which the tag device 364may be a disposable product, similar to a disposable contact lensemployed in vision correction applications.

IV. EMBEDDING A TAG DEVICE IN A CONTACT LENS

A tag device, such as an RFID tag, can be embedded in a body-mountabledevice, such as an eye-mountable device, which may be worn on the eye asa contact lens. Further, the tag device may be in RF communication witha reader device so as to enable the reader device to receive data andother information from the tag device and/or eye-mountable device.

FIG. 4A is a bottom view of an example eye-mountable device 410 (orophthalmic electronics platform), and FIG. 4B is a side view of theexample eye-mountable device 410. It is noted that relative dimensionsin FIGS. 4A and 4B are not necessarily to scale, but have been renderedfor purposes of explanation only in describing the arrangement of theexample eye-mountable device 410.

The eye-mountable device 410 is formed of a polymeric material 420shaped as a curved disk. The polymeric material 420 can be asubstantially transparent material to allow incident light to betransmitted to the eye while the eye-mountable device 410 is mounted tothe eye. The polymeric material 420 can be a biocompatible materialsimilar to those employed to form vision correction and/or cosmeticcontact lenses in optometry, such as polyethylene terephthalate (“PET”),polymethyl methacrylate (“PMMA”), polyhydroxyethylmethacrylate(“polyHEMA”), silicone hydrogels, combinations of these, etc. Thepolymeric material 420 can be formed with one side having a concavesurface 426 suitable to fit over a corneal surface of an eye. Theopposite side of the disk can have a convex surface 424 that does notinterfere with eyelid motion while the eye-mountable device 410 ismounted to the eye. A circular outer side edge 428 connects the concavesurface 424 and convex surface 426.

The eye-mountable device 410 can have dimensions similar to a visioncorrection and/or cosmetic contact lenses, such as a diameter ofapproximately 1 centimeter, and a thickness of about 0.1 to about 0.5millimeters. However, the diameter and thickness values are provided forexplanatory purposes only. In some embodiments, the dimensions of theeye-mountable device 410 can be selected according to the size and/orshape of the corneal surface of the wearer's eye.

The polymeric material 420 can be formed with a curved shape in avariety of ways. For example, techniques similar to those employed toform vision-correction contact lenses, such as heat molding, injectionmolding, spin casting, etc. can be employed to form the polymericmaterial 420. While the eye-mountable device 410 is mounted in an eye,the convex surface 424 faces outward to the ambient environment whilethe concave surface 426 faces inward, toward the corneal surface. Theconvex surface 424 can therefore be considered an outer, top surface ofthe eye-mountable device 410 whereas the concave surface 426 can beconsidered an inner, bottom surface. The “bottom” view shown in FIG. 4Ais facing the concave surface 426. From the bottom view shown in FIG.4A, the outer periphery 422, near the outer circumference of the curveddisk is curved to extend out of the page, whereas the central region421, near the center of the disk is curved to extend into the page.

A substrate 430 is embedded in the polymeric material 420. The substrate430 can be embedded to be situated along the outer periphery 422 of thepolymeric material 420, away from the central region 421. The substrate430 does not interfere with vision because it is too close to the eye tobe in focus and is positioned away from the central region 421 whereincident light is transmitted to the eye-sensing portions of the eye.Moreover, the substrate 430 can be formed of a transparent material tofurther mitigate effects on visual perception.

The substrate 430 can be shaped as a flat, circular ring (e.g., a diskwith a centered hole). The flat surface of the substrate 430 (e.g.,along the radial width) is a platform for mounting electronics such aschips (e.g., via flip-chip mounting) and for patterning conductivematerials (e.g., via microfabrication techniques such asphotolithography, deposition, plating, etc.) to form electrodes,antenna(e), and/or interconnections. The substrate 430 and the polymericmaterial 420 can be approximately cylindrically symmetric about a commoncentral axis. The substrate 430 can have, for example, a diameter ofabout 10 millimeters, a radial width of about 1 millimeter (e.g., anouter radius 1 millimeter greater than an inner radius), and a thicknessof about 50 micrometers. However, these dimensions are provided forexample purposes only, and in no way limit the present disclosure. Thesubstrate 430 can be implemented in a variety of different form factors.

In some examples, the substrate 430 may include a tag device. As such,components of the tag device may also be disposed on the embeddedsubstrate 530. For instance, a loop antenna 470, a controller 450, andsensing electronics 460 (e.g., an electronic oscillator, analytebio-sensor, etc.), such as those described with respect to FIG. 1, canbe disposed on the embedded substrate 430. The controller 450 can be achip including logic elements configured to operate the sensingelectronics 460 and the loop antenna 470. The controller 450 iselectrically connected to the loop antenna 470 by interconnects 457 alsosituated on the substrate 430. Similarly, the controller 450 iselectrically connected to the sensing electronics 460 by an interconnect451. The interconnects 451, 457, the loop antenna 470, as well as othercomponents can be formed from conductive materials patterned on thesubstrate 430 by a process for precisely patterning such materials, suchas deposition, photolithography, etc. The conductive materials patternedon the substrate 430 can be, for example, gold, platinum, palladium,titanium, carbon, aluminum, copper, silver, silver-chloride, conductorsformed from noble materials, metals, combinations of these, etc. Thecontroller 450 and sensing electronics 560 can also be implemented as asingle chip, rather than two separate connected components.

As shown in FIG. 4A, which is a view facing the concave surface 426 ofthe eye-mountable device 410, the sensing electronics 460 are mounted toa side of the substrate 430 facing the concave surface 526. In general,any electronics, electrodes, etc. situated on the substrate 430 can bemounted to either the “inward” facing side (e.g., situated closest tothe concave surface 426) or the “outward” facing side (e.g., situatedclosest to the convex surface 424). Moreover, in some embodiments, someelectronic components can be mounted on one side of the substrate 430,while other electronic components are mounted to the opposing side, andconnections between the two can be made through conductive materialspassing through the substrate 430.

The loop antenna 470 is a layer of conductive material patterned alongthe flat surface of the substrate to form a flat conductive ring. Insome instances, the loop antenna 470 can be formed without making acomplete loop. For instances, the loop antenna 470 can have a cutout toallow room for the controller 450 and sensing electronics 460, asillustrated in FIG. 4A. However, the loop antenna 470 can also bearranged as a continuous strip of conductive material that wrapsentirely around the flat surface of the substrate 430 one or more times.For example, a strip of conductive material with multiple windings canbe patterned on the side of the substrate 430 opposite the controller450 and sensing electronics 460. Interconnects between the ends of sucha wound antenna (e.g., the antenna leads) can then be passed through thesubstrate 430 to the controller 450.

V. CONCLUSION

It should be understood that arrangements described herein are forpurposes of example only. As such, those skilled in the art willappreciate that other arrangements and other elements (e.g., machines,interfaces, functions, orders, and groupings of functions, etc.) can beused instead, and some elements may be omitted altogether according tothe desired results. Further, many of the elements that are describedare functional entities that may be implemented as discrete ordistributed components or in conjunction with other components, in anysuitable combination and location.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following claims, along with the fullscope of equivalents to which such claims are entitled. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting.

What is claimed is:
 1. A method, comprising: obtaining a uniqueidentifier associated with a tag device, wherein the tag device includesan antenna and a sensor configured to obtain sensor readings that can bewirelessly transmitted to a reader device via the antenna; determining,based on the unique identifier, configuration parameters associated withthe tag device; and storing, in at least one memory, at least a portionof the configuration parameters in association with the uniqueidentifier.
 2. The method of claim 1, wherein the portion of theconfiguration parameters is a first portion of the configurationparameters, the method further comprising: communicating, by the readerdevice, at least a second portion of the configuration parameters to thetag device.
 3. The method of claim 2, wherein the second portion of theconfiguration parameters relates to configuring at least one componentof the tag device.
 4. The method of claim 3, wherein the at least onecomponent comprises at least one of an electronic oscillator, a radiofrequency transceiver, a voltage reference, or a current reference. 5.The method of claim 2, wherein the obtaining is performed by a mobilecomputing device, further comprising the mobile computing devicetransmitting at least the second portion of the configuration parametersto the reader device.
 6. The method of claim 5, wherein the at least onememory is in at least one of the reader device or mobile computingdevice.
 7. The method of claim 1, wherein obtaining the uniqueidentifier comprises scanning an optical code associated with the tagdevice, wherein the optical code encodes the unique identifier.
 8. Themethod of claim 1, wherein the portion of the configuration parametersincludes calibration information associated with the sensor, such thatmeasured values can be determined based on the sensor readings and thecalibration information.
 9. The method of claim 8, further comprising:receiving, by the reader device, data from the tag device, wherein thedata is representative of the unique identifier and a sensor readingobtained by the sensor; retrieving, from the at least one memory, theportion of the configuration parameters based on the unique identifier;and determining a measured value based on the sensor reading and theportion of the configuration parameters.
 10. The method of claim 1,wherein the tag device is in a body-mountable device.
 11. The method ofclaim 10, wherein the body-mountable device is an eye-mountable device.12. A computing system, comprising: at least one radio frequency (RF)transceiver unit; at least one processor; at least one memory, whereinthe at least one memory stores instructions that upon execution by theat least one processor cause the computing system to perform operationscomprising: obtaining a unique identifier associated with at least onetag device, wherein the at least one tag device includes an antenna anda sensor configured to obtain sensor readings that can be wirelesslytransmitted to the computing system via the antenna; determining, basedthe unique identifier, configuration parameters associated with the atleast one tag device; and storing, in the at least one memory, at leasta portion of the configuration parameters in association with the uniqueidentifier.
 13. The computing system of claim 12, the operations furthercomprising: transmitting, via the at least one RF transceiver unit, anRF signal to the at least one tag device, wherein the RF signal includesat least another portion of the configuration parameters.
 14. Thecomputing system of claim 13, wherein transmitting the RF signal to theat least one tag device comprises transmitting the RF signal to the atleast one tag device using a radio-frequency identification (RFID)protocol.
 15. The computing system of claim 12, wherein obtaining theunique identifier comprises scanning an optical code associated with theat least one tag device, wherein the optical code encodes the uniqueidentifier.
 16. The computing system of claim 15, wherein the opticalcode includes a Quick Response (QR) code.
 17. The computing system ofclaim 15, wherein the optical code encodes additional informationassociated with the at least one tag device.
 18. The computing system ofclaim 17, wherein the additional information includes a date associatedwith fabrication of the at least one tag device.
 19. The computingsystem of claim 17, wherein the additional information includes a lotnumber associated with fabrication of the at least one tag device. 20.The computing system of claim 12, wherein the computing system furthercomprises a reader device and a mobile computing device.
 21. Thecomputing system of claim 20, wherein the obtaining is performed by themobile computing device, the operations further comprising the mobilecomputing device transmitting at least another portion of theconfiguration parameters to the reader device.
 22. A non-transitorycomputer readable medium having stored therein instructions executableby a computing device to cause the computing device to performfunctions, the functions comprising: obtaining a unique identifierassociated with a tag device, wherein the tag device includes an antennaand a sensor configured to obtain sensor readings that can be wirelesslytransmitted to the computing device via the antenna; determining, basedon the unique identifier, configuration parameters associated with thetag device; and storing, in at least one memory, at least a portion ofthe configuration parameters in association with the unique identifier.23. The non-transitory computer readable medium of claim 22, thefunctions further comprising: communicating at least another portion ofthe configuration parameters to the tag device.
 24. The non-transitorycomputer readable medium of claim 22, wherein determining, based on theunique identifier, the configuration parameters associated with the tagdevice comprises: transmitting the unique identifier to a server; andreceiving the configuration parameters from the server.
 25. Thenon-transitory computer readable medium of claim 22, wherein obtainingthe unique identifier comprises scanning an optical code associated withthe tag device, wherein the optical code encodes the unique identifier.26. The non-transitory computer readable medium of claim 25, wherein theconfiguration parameters are encoded in the optical code.